When Pegah Saraf thinks about sustainability, she envisions more than just avoiding single-use plastics and practising better recycling habits.  

She thinks about the food we eat.  

As the global demand for protein grows, Saraf, a PhD candidate in Engineering professor Ravi Selvaganapathy’s lab, is exploring ways to produce meat while using fewer resources.  

Cultivated meat, which uses animal cells grown in a controlled environment to produce an alternative meat that has the same physical and chemical makeup as standard meat, is one approach that she’s been exploring in the lab.  

While cultivated meat shows promise as a sustainable, ethical alternative to traditional meat, it is not without its challenges, says Saraf. Namely, the difficulty of building a scaffold that is mechanically stable enough to support cell growth while also being suitable for food production.   

Thanks to Saraf, though, that might be changing.  

She has discovered a way to produce these scaffolds that combines the nutritional and functional advantages of plant-based biomaterials and animal cells while contributing to a more sustainable future for food production.  

And that work starts at the cellular level.  

Cultivated meat begins with tiny animal cells, which can be obtained from a small tissue sample. For Saraf’s work, which used bovine muscle-derived cells, this meant a biopsy from domestic cattle. These cells naturally know how to grow and multiply on their own, explains Saraf, but the challenge is finding a suitable foundation for these cells to grow on.  

That’s where the scaffold comes in. Think of it as a “kind of home for the cells,” says Saraf. “It’s a place where they can attach to, grow and multiply.” 

The protein-rich, cell-interactive scaffolds Saraf produced are entirely plant-based — one was constructed using soy protein isolates, and the other was constructed using pea protein isolates — making them edible, widely available and relatively inexpensive.  

Historically, plant-based scaffolds have been difficult to fabricate into stable 3D structures on their own, explains Saraf. This challenge has required researchers to combine their plant-based scaffolds with additional structural materials, such as polysaccharides, which have fewer sites for cells to bind to unless the material is modified or coated. 

Saraf’s scaffolds, on the other hand, use proteins that can provide more biologically relevant binding sites, explains Saraf. For instance, soy contains peptides that can naturally support cell attachment. 

To make their scaffold more stable, Saraf used a combination of genipin, a natural compound found in fruit extract that acts as a cross-linker for proteins, and dehydrothermal treatment (DHT), which uses a heat and vacuum treatment to stabilize the structure.  

This combination led to a scaffold that bent without breaking, is entirely edible and supports the growth of animal cells.  

But the use of genipin comes with one unique challenge: When it is used in high doses, it reacts with protein and turns the scaffold blue.   

To ensure the colour of the scaffold closely resembled that of traditional meat, Saraf’s combination of optimized, low-dose genipin with DHT resulted in a much milder pink.  

More than just its colour, one of the other signature trademarks of beef is the marbling effect caused by the mixing of fat with muscle tissue.  

This is the next challenge Saraf wants to tackle, and it starts with growing two types of cells together on one scaffold.  

“For this study, I exclusively focused on muscle cells to prove that this type of scaffold could be effective,” explains Saraf. “Next, I want to grow fat cells on the scaffold as well so we can get that marbling effect you find in store-bought meat.”  

Once the marbling is in place, Saraf plans to scale everything up. Right now, the proof-of-concept scaffold is roughly two-centimetre squares, explains Saraf.  

To get to a point where the cultivated meat can more closely resemble the size and consistency of meat you’d expect to find in a grocery store, the scaffold will need to be much larger. That means they’ll need, among other things, to generate a larger number of cells, maintain consistent oxygen and nutrient transport through thicker tissues, remove metabolic waste and achieve uniform cell distribution and differentiation.  

It also means that they’ll need to figure out how to develop a scalable system that is cost-effective, food-grade and serum-free.  

But for now, with an eye to the future, Saraf is focused on the impact of this newly designed scaffold.  

“People already care about recycling and reducing plastic waste because they know today’s choices shape their future,” says Saraf. “Because the world’s population continues to grow, food production needs to be viewed in a similar way.”  

And with consumer demand for protein increasing year over year, this will only continue to put more stress on the meat industry, which already requires a large agricultural footprint and a lot of water to meet current demands.  

That’s why, explains Saraf, cultivated meat provides such a unique opportunity — it’s not a replacement, but an alternative.  

“This work is not telling people to stop eating meat,” says Saraf. “It’s offering an alternative choice that is more ethical and more sustainable.”